Stabilized enhanced efficiency controllable release calcium cyanamide compositions

Abstract

Embodiments of a calcium cyanamide composition and method for their use are disclosed. The composition and method stabilize active ionic compositions comprising calcium cyanamide and enhance the effectiveness of calcium cyanamide alone or synergistically in combination with nitrogen-containing materials such as urea and organics, for example, manures. The composition and method also facilitate controllable site-directed delivery of the contents of the stabilized compositions. The composition and method are effective for fertilizing, soil amending, metal stabilizing and odor and organism inhibition. The compositions are stable, easily calibrated, and non-clogging for spray delivery to target sites.

We claim:  
     
         1 . A heterogeneous composition, comprising: 
 a core, the core comprising about 0.1 to about 40% of the total weight of the composition and comprising a material selected from the group consisting of calcium oxide, dicyandiamide, calcium carbide and combinations thereof; and    a shell, the shell comprising about 60 to about 99.9 percent of the total weight of the composition and comprising a material selected from the group consisting of urea, calcium cyanamide and mixtures thereof.    
     
     
         2 . The composition of  claim 1  further comprising at least one additional nitrogen-containing material.  
     
     
         3 . The composition of  claim 2  where the at least one additional nitrogen-containing material is an ammonium salt.  
     
     
         4 . The composition of  claim 3  where the ammonium salt is selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium monophosphate, ammonium diphosphate, ammonium citrate, ammonium nitrate, calcium ammonium phosphate, and mixtures thereof.  
     
     
         5 . The composition according to  claim 1  further comprising at least one non-nitrogen plant nutrient.  
     
     
         6 . The composition of  claim 5  where the non-nitrogen plant nutrient is selected from the group consisting of phosphorous, potassium, iron, copper, zinc, manganese, boron, magnesium, molybdenum, sulfur, and mixtures thereof.  
     
     
         7 . The composition according to  claim 1  where the composition further comprises at least one nitrogen-containing compound selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium monophosphate, ammonium diphosphate, ammonium citrate, ammonium nitrate, calcium ammonium phosphate, and mixtures thereof and at least one non-nitrogen plant nutrient selected from the group consisting of phosphorous, potassium, iron, copper, zinc, manganese, boron, magnesium, molybdenum, sulfur, and mixtures thereof.  
     
     
         8 . The composition according to  claim 1  where the core comprises from about 0.1 to about 10 percent of the total mass of the composition and the shell comprises from about 90 to about 99.9 percent of the total mass of the composition.  
     
     
         9 . The composition according to  claim 8  where the composition is granular.  
     
     
         10 . The composition of  claim 1  further comprising a hardening agent in the shell.  
     
     
         11 . The composition of  claim 10  where the hardening agent is formaldehyde.  
     
     
         12 . A method for making a heterogeneous composition, comprising: 
 providing a particle, the particle selected from the group consisting of a calcium oxide particle, a dicyandiamide particle and a calcium carbide particle; and    coating the particle with a material, the material comprising a substance selected from the group consisting of urea, calcium cyanamide and mixtures thereof.    
     
     
         13 . The method according to  claim 12  where the particle is from about 0.1 to 40 percent by weight of the final heterogeneous composition.  
     
     
         14 . The method according to  claim 13  where the particle is from about 0.1 to about 10 percent by weight of the final heterogeneous composition.  
     
     
         15 . The method according to  claim 14  where material is molten.  
     
     
         16 . The method according to  claim 15  where the material is molten urea and is sprayed onto the particle.  
     
     
         17 . The method according to  claim 15  where the molten material further comprises from about 0.01% to about 10% water.  
     
     
         18 . The method according to  claim 12  where the particle is coated with successive layers of the material.  
     
     
         19 . The method according to  claim 18  where the material is urea and successive layers are all urea layers.  
     
     
         20 . The method according to  claim 12  where the material further comprises a substance selected from the group consisting of ammonium sulfate, ammonium citrate, ammonium phosphate, calcium ammonium nitrate, calcium nitrate, sodium nitrate, ammonium chloride, and mixtures thereof.  
     
     
         21 . A method for making a homogeneous solid composition, comprising: 
 combining calcium cyanamide, a nitrogen-containing material, and water, where the amount of water is at least 14 times the weight of the dry calcium cyanamide, to form an aqueous material;    inhibiting aeration of the aqueous material; and    dehydrating the aqueous material to form a solid.    
     
     
         22 . The method of  claim 21  where the nitrogen-containing material is selected from group consisting of urea, manure, and combinations thereof.  
     
     
         23 . The method of  claim 21  where the nitrogen-containing material is urea and the aqueous material is saturated with urea.  
     
     
         24 . The method of  claim 21  where the aqueous material is a slurry.  
     
     
         25 . The method of  claim 21  where inhibiting aeration comprises combining and dehydrating within a container that inhibits exchange of gases with the atmosphere.  
     
     
         26 . The method of  claim 25  where the container is sealed to substantially prevent exchange of gases with the atmosphere.  
     
     
         27 . The method of  claim 25  where the container is evacuated to inhibit exchange of gases with the atmosphere.  
     
     
         28 . The method of  claim 21  where inhibiting aeration comprises combining and granulating in the presence of a gas that serves to substantially exclude the atmosphere.  
     
     
         29 . The method of  claim 28  where the gas is selected from the group consisting of nitrogen, acetylene, ammonia, argon, and mixtures thereof.  
     
     
         30 . The method of  claim 29  where the gas is acetylene and the acetylene is generated from residual calcium carbide in the calcium cyanamide.  
     
     
         31 . The method of  claim 21  where at least one additional nitrogen-containing compound is included in the aqueous material.  
     
     
         32 . The method of  claim 21  where at least one additional non-nitrogen plant nutrient is included in the aqueous material.  
     
     
         33 . The method of  claim 21  where a hardening agent is included in the aqueous material.  
     
     
         34 . A solid composition formed by the method of  claim 21 .  
     
     
         35 . A method of making a homogeneous granular composition, comprising: 
 melting together a mixture of about 0.1 to about 40 percent calcium cyanamide and about 60 to about 99.9 percent urea; and    spraying the melted mixture onto a seed particle to form a granule.    
     
     
         36 . The method of  claim 35  where the seed particle is a urea particle.  
     
     
         37 . The method of  claim 35  where the seed particle is a calcium cyanamide particle.  
     
     
         38 . The method of  claim 35  where the mixture of calcium cyanamide and urea further comprises at least one additional ingredient, selected from the group consisting of nitrogen-containing materials, non-nitrogen plant nutrients, and mixtures thereof.  
     
     
         39 . A composition comprising from about 0.01 to about 5.0 percent calcium cyanamide and from about 95 to about 99.99 percent animal excreta where the animal excreta further comprises water in an amount at least 14× the weight of the calcium cyanamide.  
     
     
         40 . The composition of  claim 39  comprising from about 0.01 to about 1.0 percent calcium cyanamide and from about 99 to about 99.99 percent animal excreta.  
     
     
         41 . The composition according to  claim 39  where aeration of the composition is inhibited by a method selected from the group consisting of placing the composition in a closed container, placing it in a sealed container, a gas that inhibits gas exchange with the atmosphere gases, and combinations thereof.  
     
     
         42 . The composition according to  claim 39  where the animal excreta is an aqueous slurry of manure.  
     
     
         43 . A method for providing nutrients to plants, comprising: 
 adding a calcium containing compound selected from the group consisting of calcium cyanamide, calcium oxide, calcium carbide, and mixtures thereof to water to form an aqueous composition; and    inhibiting aeration of the aqueous composition until it is applied to provide nutrients to plants.    
     
     
         44 . The method of  claim 43  where the calcium containing compound is calcium cyanamide that further comprises calcium oxide and calcium carbide and is added to at least 14× its weight in water. 25  
     
     
         45 . The method of  claim 44  where the aqueous composition is a sprayable slurry.  
     
     
         46 . The method of  claim 44  where solids are removed from the aqueous composition before it is applied to provide nutrients to plants.  
     
     
         47 . The method of  claim 46  where solids are removed from the aqueous composition by a method selected from the group consisting of filtration, centrifugation, and decantation.  
     
     
         48 . The method of  claim 43  where the aqueous composition further comprises urea.  
     
     
         49 . The method of  claim 48  where urea is present in an amount from about 0.01% to about its saturation limit in the aqueous composition.  
     
     
         50 . The method of  claim 43  where aqueous composition further comprises animal excreta.  
     
     
         51 . The method of  claim 43  where aeration is inhibited until the composition is applied to soil.  
     
     
         52 . The method of  claim 43  where aeration is inhibited until the composition is applied foliarly to plants.  
     
     
         53 . The method of  claim 43  where aeration is inhibited until the composition is added to additional water and applied to plants through an irrigation system.  
     
     
         54 . The method of  claim 53  where the irrigation system is a fertigation/nitrigation system.  
     
     
         55 . A method for enhancing plant growth, comprising: 
 providing a granular composition, the composition comprising a calcium cyanamide core and a urea shell where the calcium cyanamide core is from about 0.1 to about 40 percent by weight and the urea shell is from about 60 to about 99.9 percent by weight; and    applying the granular composition to soil to induce plant growth.    
     
     
         56 . The method of  claim 55  further comprising adding water to the granular composition to form an aqueous composition simultaneous with or subsequent to applying the granular composition to soil.  
     
     
         57 . The method of  claim 56  where aeration of the aqueous composition is inhibited until the aqueous composition is applied to enhance plant growth.  
     
     
         58 . The method of  claim 55  where applying comprises application of the aqueous composition to soil.  
     
     
         59 . The method of  claim 55  where applying comprises application of the aqueous composition foliarly.  
     
     
         60 . A method of composting animal excreta, comprising: 
 adding about 0.1 to about 1.0 percent by weight calcium cyanamide to animal excreta, where the animal excreta contains water in an amount at least 14× the mass of the calcium cyanamide to form a mixture; and    inhibiting mixture aeration.    
     
     
         61 . The method of  claim 60  where inhibiting aeration of the mixture comprises forming the mixture in a closed container.  
     
     
         62 . The method of  claim 61  where the closed container is sealed to substantially prevent gas exchange between the container and the atmosphere.  
     
     
         63 . The method of  claim 60  where inhibiting aeration of the mixture comprises forming the mixture in a container, the container also holding a gas selected from the group consisting of nitrogen, argon, ammonia, acetylene, and mixtures thereof that serves to inhibit gas exchange between the container and the atmosphere.  
     
     
         64 . The method of  claim 60  where the animal excreta is liquidized manure.  
     
     
         65 . The method of  claim 60  where adding calcium cyanamide comprises adding calcium cyanamide in a form selected from the group consisting of calcium cyanamide fines, granulated calcium cyanamide, a homogeneous granule comprising calcium cyanamide and urea, a heterogeneous granule comprising calcium cyanamide and urea, an aqueous composition comprising calcium cyanamide dissolved in greater than 14× its weight in water, and mixtures thereof.  
     
     
         66 . The method of  claim 60  further comprising applying the mixture to soil by slurry spraying.  
     
     
         67 . A method of enhancing plant growth, comprising; 
 combining greater than about 40 parts of water with about 10 parts of a combination of calcium cyanamide and urea, where the about 10 parts of a combination of calcium cyanamide and urea further comprises from about 0.1 to about 3 parts calcium cyanamide and from about 7 to about 9.9 parts urea to form a first aqueous composition;    inhibiting aeration of the first aqueous composition;    adding the first aqueous composition to additional water to form a second aqueous composition; and    applying the second aqueous composition to enhance plant growth.